function f = PlotMainField(obj, MainFieldData)
    if nargin ==1 
        MainFieldData = obj.SystemInfo.MainField;
    end
    
    norm = MainFieldData.fitting.norm;
    range = MainFieldData.fitting.range;
    bz0=MainFieldData.fitting.bz0;
    Gamma = MainFieldData.fitting.width;
    hight = MainFieldData.fitting.hight;
    xList = linspace(range(1), range(2), 101);
    yList = sqrt(MainFieldData.fitting.result(xList))*norm;
    rangeCenter = mean(range);
    
    yPhaseList = (atan((xList-bz0)/Gamma) - atan((rangeCenter-bz0)/Gamma))/pi*180;
    
    dataR = MainFieldData.signal.getNodeData(1); bzList = dataR.x; rList=dataR.y;
    dataTheta = MainFieldData.signal.getNodeData(2); phaseList = dataTheta.y;
    
    f = figure('Name', sprintf('RFResonance[%s]',datestr(MainFieldData.timestamp)), 'WindowStyle', 'docked');
    ax1 = subplot(2, 1, 1, 'Parent', f);
    plot(ax1, bzList, rList, 'b.-', xList, yList, 'r-'); grid on;
    xlabel(ax1, 'Bz0 Voltage (V)'); ylabel(ax1, 'Amplitude (V)');
    title(ax1, sprintf('Resoance Bz0=%5.4f V, \\Gamma=%5.3fV, Vmax=%5.3e V', bz0, Gamma, hight), 'Interpreter', 'tex');
    ax2 = subplot(2, 1, 2, 'Parent', f);
    plot(ax2, bzList, phaseList/pi*180, 'b.-', xList, yPhaseList, 'r-'); grid on;
    xlabel(ax2, 'Bz0 Voltage (V)'); ylabel(ax2, 'Phase (degree)');
end